DKIM TXT DNS record mail._domainkey exists but says it doesn't

I followed the excellent article: to set up DKIM on my server. I created the two TXT records exactly as required. My domain is called However the authentication check using a test email to: returns the following in the DKIM section stating that doesn’t exist (see below), when it does. Having read as many blog articles as I could find about this I have ensured the text is in quotes and I am sure it is not a propagation issue as I used (and other similar online tools) to check for which was found as a TXT record ok.

Also I note in the report below, it reports the DNS record as TXT (NXDOMAIN) - whatever that means.

No idea what to do next. Can someone please help?


DKIM check details:

Result: permerror (key “” doesn’t exist) ID(s) verified: Canonicalized Headers:’0D’‘0A’ from:John’20’’0D’‘0A’ subject:test’0D’‘0A’ date:Sun,‘20’23’20’Apr’20’2017’20’15:53:34’20’+0800’0D’‘0A’ dkim-signature:v=1;'20’a=rsa-sha256;'20’c=relaxed/simple;'20’;'20’s=mail;'20’t=1492934013;'20’bh=frcCV1k9oG9oKj3dpUqdJg1PxRT2RSN/XKdLCPjaYaY=;'20’h=To:From:Subject:Date:From;'20’b=

Canonicalized Body: ‘0D’‘0A’

DNS record(s): TXT (NXDOMAIN)

NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25’s PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM.

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Hello there,

You can use a DKIM checker tool like the one provided from mxtoolbox and check whether the generated key is valid.

I’ll also highly recommend not to send emails via port 25 as this is insecure and a lot of email providers will discard any emails coming from it. You can also use an email provider like Sendgrid to send your emails.

Hope that this helps! Regards, Alex


When using MXToolbox, I was able to verify the DKIM entry easily. I’m seeing the following:

v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDfWHolALh8Kohz+hSyWWRArUQJbo+lDAKKIUIQ39s3V/AQOO4IcihyF7s8ZFl936NcF6wcpEHXzvnYt5g19+s0VtY8Hc+CM8+a3AC4nz1QuGeitzNDp8f/mNkjZA33k3cnMFj5286Aej/YYsMzMsUQbRzXgYk9MKphJEBAIpYc2wIDAQAB

It is possible that at the time of checking, the DNS entry hadn’t fully propagated, thus when they did a check, it failed. On my end, as of this reply, it’s showing up and appears valid.